title: Transport of the botulinum neurotoxin-associating protein, nontoxic nonhemagglutinin, across the rat small intestinal epithelial cell monolayer.
abstract: Botulinum neurotoxin (BoNT) associates with nontoxic nonhemagglutinin (NTNHA) yielding a complex in culture. BoNT and NTNHA have similar domain organizations, implying that they share common functions, although this remains unclear. Here, we examined cell monolayer transport of serotype D NTNHA in the rat intestinal epithelial cell line IEC-6. NTNHA and BoNT both bound to the cell and were transported across the cell layer. NTNHA contains a QXW motif and a β-trefoil fold, both common in sugar chain-recognizing proteins, whereas the QXW motif is absent in all BoNT serotypes. This could explain the distinct sugar chain-recognizing properties of NTNHA and BoNT.
authors.affiliation: Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, Abashiri, Japan.
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Miyashita
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Sagane
authors.forename: Koichi
authors.initials: K
authors.lastname: Niwa
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D001905:Botulinum Toxins / Q000378:metabolism; D002460:Cell Line; D004847:Epithelial Cells / Q000378:metabolism*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D021381:Protein Transport; D051381:Rats; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; C096325:botulinum toxin type D; D001905:Botulinum Toxins
keywords: Clostridium botulinum; QXW motif; botulinum neurotoxin; intestinal epithelial cell; nontoxic nonhemagglutinin; β-trefoil